Help, please how am I going to write my story in the first person, what should be my first sentence be

Okay, so you have a good topic, which looks to be about a black lesbian girl in a all white boarding school. Okay... so first person is I, me, you know. You have to figure out what kind of tense it'll be. Is it happening RIGHT NOW, or is it like, telling a story? I mean, you can change it up and experiment until you like how it sounds, that's what I do. So here's some examples to give you some ideas. (past tense is the most common, and it's easier to work with, but you choose what you want.)

First person past tense: I couldn't believe it was happening. Me, a black girl, going to an all whites school?

First person present tense: I can't believe this is happening. Me, a black girl, going to an all whites school?

you can ask more in the comments if you're still stuck.